This just sounds like you hid the settings in the print window, other wise Pages is clearly the problem because when a feature works in every application except one, the application with the issue is the problem.
So if it is just an issue with Pages and it isn't that you hid the driver details you would need to contact Apple, not Xerox.
I used to be able to Print to Fax. Simply by selecting Print in my document then using the Fax version of the Xerox 6505DN Driver. Upon pressing print a window opened where I could enter the name and number of the recipient.
Its still working on some software but no longer works on Apples PAGES which of course is where I need it most.
Anyone can help me fix this???